Headrest with adhesive attachment

ABSTRACT

A PROTECTIVE COVER SUCH AS A HEADREST IS FORMED FROM A SHEET OF NONWOVEN FABRIC BEARING ALONG ONE EDGE A STRIP OF ADHESIVE, SAID ADHESIVE BEING CAPABLE OF ADHERING FIRMLY TO A SMOOTH SURFACE SUCH AS A METAL OR PLASTIC STRIP, BUT SHOWING LITTLE OR NO ADHESION TO THE FABRIC OF THE HEADREST.

Sept 12 1972 D. B. BUTLER 3,691,005

HEADREST WITHADHESIVE ATTACHMENT Filed Nov. 16, 1970 United States Patent Oice Patented Sept. 12, 1972 3,691,005 HEADREST WITH ADHESIVE ATTACHMENT David B. Butler, Wickford, R.I., assignor to The Kendall Company, Boston, Mass. Filed Nov. 16, 1970, Ser. No. 89,717 Int. Cl. C091' 7/02; B32b 7 /14 U.S. Cl. 161--167 2 Claims ABSTRACT F THE DISCLOSURE This invention relates to disposable protective coverings, and more particularly to disposable headrests which may be temporarily attached to the back of a seat or chair by adhesive union.

For the sake of comfort and appearance, seats in public conveyances such as airplanes, buses, and trains are customarily upholstered with fabrics of a more or less durable nature. To prevent soiling of the portion of the fabric with which the passengers head comes in contact, and to provide an esthetic and sanitary appearance, it has long been the practice to provide a temporarily-attached piece of fabric, called a headrest, to the upper portion of the seat. Earlier conventional headrests were pieces of towel-like fabric provided with hemmed eyelets which fitted over metal buttons which were permanently secured to the top of the seat. The inconvenience and growing expense of collecting, sorting, and laundering such items gradually led to the use of disposable covers, of paper or nonwoven fabrics, to be used by one passenger and then discarded. Also in the interest of economy and time-saving, various means have been proposed for attaching such covers to the seat. One such is described in U.S. Pat. 3,266,841, where a cover is provided with an elongated thread attached parallel to one edge, said thread bearing a plurality of loop portions intended to engage with a set of hook-like plastic filaments fixed permanently to the top of the seat.

One objection to the use of such devices is that single filaments, or small groups of filaments, break off during the attachment or detachment of the yarn from the plastic hooks, which gradually accumulate a bed of filamentary residue which is both unsightly and interferes with the function of engagement.

lIt is with improvements in the art of providing disposable covers that the present invention is concerned.

' It is a primary object of this invention to provide a novel disposable protective covering capable of rapid and simple application to and removal from an area to be protected.

It is an additional object of the invention to provide a disposable cover comprising an adhesive strip capable of being firmly affixed to a smooth-surfaced strip, but incapable under normally pressures of being afiixed to a fabric.

The invention will be better understood by reference to the following description and drawings, in which:

FIG. 1 is a perspective view of a protective cover made according to this invention,

FIG. 2 is a cross-sectional view of the tape element 14 of FIG. l, and

FIG. 3 is a fragmentary perspective view of the protective cover of this invention, partially secured to the upper portion of the back of a seat.

Basically, the present invention comprises the provision of a protective cover of nonwoven fabric which has afiixed at or close to one marginal edge a strip of pressure-sensitive adhesive-faced material capable of adhering more or less securely to a smooth surface, but incapable of adhering to the body of the cover itself. The nature of adhesive masses suitable for such purposes will be more fully explained below.

Referring to FIG. 1, there is shown a protective cover 10 consisting of a generally rectangular sheet of nonwoven fabric 12, which has fastened across its width and near the upper marginal portion thereof a strip 0f adhesive tape 14, with the adhesive surface uppermost-ie., away from contact with the body of the cover. The term nonwoven fabric herein is defined as a soft, compliant, absorbent, and preferably air-permeable sheet material comprising textile-length fibers, papermaking fibers, or mixture thereof.

As shown in FIG. 2, the tape strip 14 is of conventional design, comprising a base 16 of fabric paper, film or the like, bearing on its surface a layer 18 of pressure-sensitive adhesive which has little or no tendency to stick to the body 12 of the nonwoven cover. The tape l14 may be afiixed to the cover by any convenient means such as by sewing, stapling, or by provision on its other face of a layer of high-tack adhesive which does adhere to the body 12 of the cover.

FIG. 3 shows in perspective a seat or upholstered chair 20, across the top of the back of which is fastened permanently a strip of smooth-surfaced material 22, such as a glossy-surfaced smooth metal or plastic strip. In practice, the cover 10 is positioned against the back of the seat with the adhesive-surfaced strip 14 in contact with the smooth surface of the permanently-fixed strip 22. The adhesive surface 18 of the tape strip 14 may be fixed in position by running the fingertips along the back of the cover along the length of the tape.

During installation, as for example on bus or airplane seats, a stack of such covers may be carried draped over one forearm. Also, in shipping, the covers may be stacked one on top of another, with no interleaving of separators between covers and no releasable strips covering the adhesive mass, since the manipulation and disposal of such separating devices is time-consuming and leads to unsightly waste that must be disposed of.

It will be appreciated, therefore, that the adhesive coating 18 on the tape 14 must be of such a nature that it does `not adhere to the surface of an adjacent cover with which it may be in contact. It must at the same time adhere rather firmly to the smooth surface of the plastic or metal strip permanently fixed to the back of the seat, and must be readily peelable therefrom with substantially no adhesive mass residue being left on the smooth strip.

In order for an adhesive mass to show little or no adhesion to the relatively rough surface of a nonwoven fabric cover, the mass should have a smooth surface and a high degree of internal cohesion-Le., a low compliancewso that it does not flow spontaneously or under moderate pressure into the irregularities of the fabric. In such a mass, the adhesive makes contact with the nonwoven fabric only at the fiber tips, or along short segments of fiber lengths, and adhesion of one cover to another, or blocking as it is sometimes called, is avoided. At the same time, the adhesive mass must have sufiiciently high adhesion to surfaces with which it makes a large area of contact so that the positioned cover resists displacement due to head or back movements.

Adhesive masses fulfilling these requirements are characterized, it has been found, as flow tack, moderate to high adhesion masses, as they are described in the adhesive art.

In characterizing the adhesive masses suitable for use in this invention, tack is conveniently measured by the tack testing apparatus described in U.S. Pat. 3,214,971, wherein a probe is brought into contact with an adhesive surface under a predetermined contact pressure, for a specified time, and then is withdrawn at a predetermined rate. The force necessary to break the bond between the probe surface and the adhesive mass is taken as a measure of the tack of the adhesive.

Using the above apparatus, with a smooth-surfaced probe 0.5 centimeter in diameter, ybrought to contact at a rate of one centimeter per second, held under a load of 100 grams per square centimeter, and separated at a rate of one centimeter per second, the force in grams measuring tack for a variety of adhesive masses was determined. Very tacky adhesive masses have values of 2,000 grams or over: a commercial brand of transparent tape had a rating of about 1,000 grams. It has been found that non-blocking tapes suitable for use in this invention have values of under 500, and preferably under 300, grams.

Adhesion, in a distinction to tack, is measured according to ASTM test D 1000-68, wherein a strip of adhesive tape is peeled from a smooth polished stainless steel plate to which it has been made to adhere under specified conditions. A rating of over 35 ounces indicates a highly adhesive mass; below 34 ounces is characteristic of moderate adhesion. It has been found that preferred adhesive masses for use in this invention have an adhesion to polished surfaces of not less than 8 ounces per inch width of tape when tested as set forth above.

In a modification of the above peel test, a length of tape one inch wide is pressed for 8 inches of its length onto a one-inch wide strip of substrate 10 inches or more long, the upper uncovered portion of which substrate strip is clamped into the upper jaws of an Instron Tensile Tester in a vertical position. The upper edge of the tape is peeled back upon itself and fastened into the lower jaw of the Instron. Separation of the jaws measures the force necessary to peel the tape from the substrate.

In a representative series of tests, an adhesive mass suitable for use in this invention was prepared by the copolymerization of 90 parts of ethyl acrylate and 10 parts of a maleic half-acid amide, the latter being the reaction product of reacting one of the acidic groups of a tertiary amine such as PRIMENEN (a Rohm and Haas trademark), as set forth in U.S. Pat. 3,299,010. The mass was solvent-spread onto an acetate film base and slit into one-inch wide rolls. Strips of this tape were then affixed to a variety of substrate strips and tested as set forth above.

The forces necessary to peel the one-inch strips of tape from various substrates were:

Ounces Smooth acrylic sheets or polished steel 9.6 Grained stainless steel 6.4 Manila board 3.2 Nonwoven fabric 0.0

The nonwoven fabric was a spot-bonded mixture of 25% polypropylene fibers, 75% viscose rayon produced as set forth in U.S. Pat. 3,507,943.

By contrast, a commercial double-faced tape gave the following values in a parallel series of tests:

Ounces Smooth acrylic sheet 41.6 Grained stainless steel 24.0 Manila board 8 Nonwoven fabric 8 Given the above physical constants desirable in the adhesive mass, it is possible for one skilled in the adhesive mass art to devise a suitable low-tack, moderate to high adhesion composition from a variety of polymers, modifying the natural properties of the polymer by various additives and by the method of compounding the mass.

The acrylic polymer mass described above is to be taken as illustrative, and not restrictive, since similar suitable low tack, moderate-to-high adhesion masses can be made in other ways known to those skilled in the art. For example, they may be made by solvent spreading of elastomeric materials such as triblock copolymers or the A-B-A type, where A is polystyrene and B is either cis polybutadiene or cis polyisoprene. Suitable masses can also be formed by the hot calendering of adhesive masses comprising blends of reclaimed rubber and smoked sheet; as follows:

parts of gray reclaimed rubber and 30 parts of smoked sheet were kneaded in a Banbury mixer for 6 minutes, together with 24 parts of a clay filler. 144 parts of this mixture were then milled for 30 minutes at 260 F.300 F. together with 40 parts of modified wood rosin, 64 parts of zinc oxide, and 4 parts of a conventional antioxidant. This mass was then calendered onto a tightly woven smooth cotton fabric backing. The resulting tape adhered readily and firmly when lightly pressed onto a smooth acrylic sheet, but showed no adhesion to the nonwoven fabric described above.

Although the present invention has been illustrated primarily with reference to a headrest, it is equally applicable to variety of other uses, such as the anchorage of sheets 0r covers to hospital beds or examining tables, the temporary fixation of disposable cubicle draperies, and similar uses.

Having thus described my invention, I claim:

1. A protective cover for attachment to a surface, said surface bearing at least in part a smooth element capable of adhesion to a strip of pressure-sensitive adhesive tape, which comprises:

a sheet of nonwoven fabric having afiixed to at least one marginal portion thereof a strip of pressuresensitive adhesive tape,

the adhesive portion of said tape lying on the outer surface of said tape and having little or no adhesive affinity for the material of the body of said cover,

but having substantial adhesive affinity for the surface of said smooth element.

2. The cover according to claim 1 in which the adhesive mass on the adhesive tape has a tack value of not greater than 300 grams and an adhesion of not less than 8 ounces by peel test from a polished steel surface.

References Cited UNITED STATES PATENTS 2,670,315 2/1954 Rider 156-305 1,779,588 10/1930 Doty et al. 117-44 2,804,419 8/1957 Woskin et al 156-305 3,472,727 10/ 1969 Guerard 161-51 3,503,568 3/1970 Galley l61-l46 3,351,515 11/1967 Muttera, Jr. 161-167 2,880,862 4/ 1959 Sermattei 17-68.5 UX

ALFRED L. LEAVITT, Primary Examiner M. F. ESPOSITO, Assistant Examiner U.S. C1. X.R. 

